svn commit: r195960 - in head/sys/dev/usb: . controller input
Robert N. M. Watson
rwatson at FreeBSD.org
Sun Aug 2 19:58:17 UTC 2009
On 2 Aug 2009, at 20:29, Alfred Perlstein wrote:
> * Robert Watson <rwatson at FreeBSD.org> [090801 15:15] wrote:
>> On Sat, 1 Aug 2009, Hans Petter Selasky wrote:
>>>>> This has slowed down core dumps very significantly. What used
>>>>> to take
>>>>> 10-15s on my system now takes around 3 minutes. A simple test
>>>>> is to
>>>>> break into ddb and "call doadump" with or without this rev. I
>>>>> have a
>>>>> serial console on this machine and so I can use ddb whether the
>>>>> USB keyboard works or not.
>>> It's because there is a DELAY(1000) in the UKBD's polling routine
>>> so that
>>> key- repeating will work, no magic.
>> Given a choice between dumping 10x faster and having automatic key
>> in DDB, I'd lean towards the former. :-)
> Robert, and *@freebsd.org,
> Hans should be back in a day or so to address this. If critical I can
> probably back out the offending code, but I think it makes sense to
> wait a few days more for a more comprehensive fix.
That's my feeling too -- however, I think it would be useful to
generate a small concept test patch that disables the key repeat
behavior and see if it restores some/all performance. Scott's argument
suggests only some, but perhaps we'd get quite a bit, which is what
we're looking for. We wouldn't commit the patch but it would let us
know we're on the right track.
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